Plot A young man named Park Shi-On (Joo Won) has savant syndrome and a developmental disability. His mental age is that of a 10-year-old, but he becomes a paediatric surgeon. Meanwhile, Kim Do-Han (Joo Sang-Wook), who is the best paediatric surgeon, finds himself frequently in confrontation with Park Shi-On.

When Park Shi-On was a child, he was quite different from other children due to having savant syndrome. Other children did not want to hang around him. Shi-On was always alone, but he did have his older brother and a rabbit. His older brother always took care of Shi-On. Meanwhile, Shi-On’s father was violent and abusive. He even killed Shi-On’s pet rabbit.